Shotgun choke



Oct. 27, 1953 w. -F. COBB 2,656,638

SHOTGUN CHOKE Filed April 5, 1950 is m INVENTOR.

[Kala/vi 6013.5

Patented Oct. 27, 1953 UNITED STATES PATENT OFFICE SHOTGUN CHOKE William F. Cobb, Utica, N. Y.

Application April 5, 1950, Serial N 0. 154,151

3 Claims.

This invention relates to chokes of the adjustable type for controlling the pattern of shot charges expelled from a shotgun.

The invention has as its object a choke of the type referred to embodying a simplified structure consisting only of two parts, so designed that they are particularly economical to manufacture, and whereby one part can be quickly and conveniently adjusted to effect all types of shot patterns to and including a full choke.

The invention consists in the novel features and in the combinations and constructions hereinafter set forth and claimed.

In describing this invention, reference is had to the accompanying drawings in which like characters designate corresponding parts in all the views.

Figure 1 is top plan view of a choke structure embodying my invention.

Figure 2 is a sectional view taken on line 22, Figure 1.

Figure 3 is a side elevational view of the control sleeve.

Figure 4 is an end elevational view looking to the right, Figure 3.

Figure 5 is an enlarged fragmentary sectional View of the forward end portion of the supporting sleeve.

The structure consists of an outer supporting sleeve ID and an inner pattern control sleeve II. The supporting sleeve is internally threaded at its rearward end for threaded attachment to the muzzle of the shotgun barrel l2, and may be secured in fixed position, as by a small set screw l3. The forward portion of the supporting sleeve has a bore larger than the bore of the shotgun barrel l2 and is provided intermediate its ends with internal threads to receive the rear externally threaded portion 14 of the control sleeve.

The forward end of the supporting sleeve I0 is formed with a conical bore and the forward portion of the control sleeve is slotted, as at l5, or otherwise formed, to provide a plurality of yieldingly contractile segments 5, the outer portions of these segments being formed with an inclined cam surface I l complemental to the conical bore of the outer sleeve, whereby when the sleeve H is threaded into the supporting sleeve, the segments [6 are contracted to reduce the bore of the sleeve.

The forward end of the sleeve I is of cylindrical form and provided with knurling, as indicated at l8, so that the sleeve may be conveniently turned in the supporting sleeve I 0. The sleeve ID is swedged or formed adjacent its forward end with an indentation l9 causing displacement of the metal within the thickness of the sleeve, and forming a projection 20 on the conical bore of the sleeve and extending axially there of and being cooperable with the slots [5 in the pattern control sleeve to yieldingly retain the sleeve in adjusted position.

The sleeve II is bored to have a diameter substantially the same as the bore of the gun barrel. The threaded engagement between the sleeves is of such pitch relative to the incline surfaces I! so that upon rotating the pattern control sleeve, thesegments l6 are contracted to change the bore from full cylinder to full choke. The outer end face of the segments [6 may contain indicia, as shown in Figure 4, to visibly indicate the pattern for which the sleeve is adjusted, these indicia being applied to be read when the adjacent slot is engaged by the detent '20. The bore of the sleeve at the rear end thereof is of conical form, as shown at 2|.

The outer sleeve I0 is preferably proportioned in length to provide an expansion chamber 25. intermediate the end of the barrel I 2 and the. sleeve H, the sleeve being formed with a plu-. rality of groups of elongated slots or apertures; 26 to permit the escape of gas from the expan-. sion chamber and effecting a substantial reduc-. tion in the recoil of the gun, as will be Well un-- derstood. A sight 28 may be afiixed to the outer;

sleeve Hi.

It will be observed that my choke structure embodies only the inner and outer sleeves which are economical to produce, and the arrangement is such that without the use of tools, or the substitution of parts, the shot pattern can be conveniently adjusted over the entire range.

What I claim is:

1. A shotgun choke structure comprising an outer sleeve adapted to be secured to the muzzle of a shotgun barrel and being internally threaded intermediate its ends, a shot pattern control sleeve positioned in the forward end of said outer sleeve, said pattern control sleeve having its forward portion formed with yieldingly contractile segments extending outwardly from the forward end of said outer sleeve, said pattern control sleeve having its rear portion formed for threaded engagement with the outer sleeve, the forward end of said outer sleeve being formed with a conical bore and the forward end portions of said segments contiguous to said conical bore having inclined surfaces complemental to said conical bore and being cooperable to contract said segments when the pattern sleeve is threaded into said outer sleeve.

2. A shotgun choke comprising an outer supporting sleeve adapted to be attached to the muzzle of the gun barrel and being threaded internally intermediate its ends, a pattern control sleeve threaded into the forward end of said supporting sleeve and extending outwardly from the forward end thereof, the forward portion of said. pattern control sleeve being slotted to form yieldingly contractile segments having inclined surfaces coopeiable w'ith the forward end of said outer sleeve to contract said segments as the pattern sleeve is threaded into said supporting sleeve, and the forward end of said supporting sleeve contiguous to said inclined surfacesbe'mg formed with an integral detent rib engaging the slots of said pattern control sleeve.

3. A choke for shotgun barrell comprisingan outer supporting sleeve formed at its rearward end for threaded engagement with a shotgun barrel and having an expansion chamber arranged forwardly of the muzzle of the barrel, said sleeve being formed with "an internally threaded portion forwardly of said expansion chamber and having a portion extending forwardly of said threaded portion, said outer sleeve being formed with a conical bore at its forward end, a shot pattern control sleeve positioned in the forward portion of said supporting sleeve and having threaded engagement at its inner end with the internally threaded portion of the outer sleeve to effect axial movement of the pattern control sleeve relative to said outer supporting sleeve, said pattern control sleeve being formed at its forward end with a plurality of yieldingly contractile segments extendingforwardlyfrorn the forward end of salid out'er sleeve and having inclined surfaces cooperating with said conical bore upon axial movement of the pattern sleeve to effect radial ih'ovement of said segments.

WILLIAM F. COBB.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 'Lfl'78;26'0 "Cutts Aug. 19, 1930 1;8-925522 W hite -I3ec. 27 1932 2,153,246 Gibson Apia-4,1939 2,398,298 Finlay 'et 'al. Apr/9,1946 2731531147 Egleson Nov. 16, 1948 2 466 184 Hi-lburn Apr. 5, 1-949 2,490;829 N011 -Dec. 1:3, 1949 

